We installed ngsolve via pip (very convienent),

pip install jupyter numpy scipy matplotlib

pip install --pre ngsolve

pip install webgui_jupyter_widgets

But the umfpack direct solver is not automatically installed. Any idea to get umfpack from pip?

Hello,

As I understand it, umfpack is not included by default on the pip version of ngsolve.

To use umfpack you need to install it system-wide (using the suitesparse package) and maybe need to compile ngsolve from source instead of via pip with the necessary CMake flags if it can’t find it on it’s own.

If I’m correct in the pip installer there is due to size only one external direct inverse available. On mac m1 where there is no pardiso we build umfpack, else we use the pardiso from mkl

a (quite) easy way to use umfpack via pip would be to use scipy. There is an option to get umfpack from scipy (also needs system packages), then just converting the matrix to scipy sparse matrix and solving there worked for me some time ago.

But if you just need a direct (non)symmetric solver, use pardiso

I see, but I am not satisfied about pardiso solver… less robust than umfpack for nonsymmetric systems (although a bit faster)